新橙皮苷二氢查耳酮工艺研究

以新橙皮苷为起始原料,制备新橙皮苷二氢查耳酮,通过对碱(氢氧化钠)用量、催化剂用量、反应温度、氢气压力、搅拌速度、反应时间等关键因素的单因素实验,对制备工艺进行了研究,建立了适用于工业化生产的方法,最佳合成的工艺为:新橙皮苷与氢氧化钠的质量比为1∶0.3,新橙皮苷与催化剂(阮尼镍)的质量比为1∶0.1,搅拌速度为150转/分钟,反应温度为25℃,反应时间为10小时。     

钯碳对合成新橙皮苷二氢查尔酮的影响

在碱性条件下,以新橙皮苷为原料、钯碳(Pd/C)为催化剂合成新橙皮苷二氢查尔酮(NHDC),研究新橙皮苷与催化剂的投放比例、催化剂的循环次对产率的影响。结果表明,新橙皮苷与催化剂比例为4∶1时,该条件下NHDC的产率最大,产率接近99%;循环次数与产率成反比,循环1~5次时,产率始终在80%以上,循环次数为1时产率最高。     

Low-calorie sweeteners in food and food supplements on the Italian market

This study determines the occurrence and concentration levels of artificial low-calorie sweeteners (LCSs) in food and food supplements on the Italian market. The analysed sample set (290 samples) was representative of the Italian market and comprised of beverages, jams, ketchups, confectionery, dairy products, table-top sweeteners and food supplements. All samples were analysed via UPLC-MS/MS. The method was in-house validated for the analysis of seven LCSs (aspartame, acesulfame-K, saccharin, sucralose, cyclamate, neotame and neohesperidin dihydrochalcone) in food and for five LCSs (aspartame, acesulfame-K, saccharin, cyclamate and sucralose) in food supplements. Except for cyclamate in one beverage which exceeded the maximum level (ML) with 13%, all concentrations measured in food were around or below the ML. In food supplements, 40 of the 52 samples (77%) were found to be above the ML, with exceedances of up to 200% of the ML.     

新橙皮苷的提取及鉴定

通过条件试验,确定了以95%甲醇为提取剂的新橙皮苷索氏提取工艺条件,即橙皮渣与提取剂的料液比为1 g:10 mL,在水浴温度90℃条件提取4 h,提取浓缩液的pH控制在4～5;在此条件下产品收率为0.65%～0.68%.产品经熔点测定和光谱鉴定,结果与文献一致.     

Evaluation of different solvents on flavonoids extraction efficiency from sweet oranges and ripe and immature Seville oranges

The effects of different ethanol (50%, 80% and 100%) and methanol (50%, 80% and 100%) aqueous solutions on extraction efficiency of flavonoids from sweet orange (SO) peels, ripe bitter orange (RBO) and immature bitter orange (IBO) were investigated. The highest amount of naringin was found in SO peels, compared to RBO and IBO. UHPLC-HRMS/MS results confirmed the presence of p-coumaric acid and quinic acid in all the three types of oranges while there were 90.91% and 20% possibilities for detecting caffeic acid in RBO and SO, respectively. The probabilities of detecting naringenin from IBO, RBO and SO were 100%, 63.64% and 40%, respectively. The highest neohesperidin and naringin amounts were obtained in RBO. Using 80% methanol was recommended for extracting flavonoids from SO to obtain the highest Soxhlet and precipitation yields whereas 100% ethanol was the most suitable solvent to extract flavonoids from RBO and IBO.     

N-乙酰吗啉的合成及市场应用情况

综述了N-乙酰吗啉的合成及市场应用情况。目前N-乙酰吗啉的生产方法有乙酸法、乙酸酐法、乙酰氯法、乙烯酮法、乙酸酯法等,其中乙酸法和乙酸酐法生产工艺较优,用于工业化生产符合我国国情。N-乙酰吗啉的市场应用情况主要是应用在农药中间体、天然气脱硫和芳烃抽提中,继续深入研究N-乙酰吗啉的其它应用领域对其市场更全面推广具有一定的现实意义。     

新橙皮苷的提取及鉴定

通过条件试验,确定了以95%甲醇为提取剂的新橙皮苷索氏提取工艺条件,即橙皮渣与提取剂的料液比为1 g:10 mL,在水浴温度90 ℃时提取4 h,提取浓缩液的pH控制在4～5.在此条件下产品收率为0.65%～0.68%,产品经熔点测定和光谱鉴定,结果与文献一致.     

响应面分析优化新橙皮苷二氢查尔酮合成工艺条件研究

以20g新橙皮苷为原料,催化加氢合成新橙皮苷二氢查尔酮（NHDC）。通过单因素实验,确定响应面实验因素与中心水平。根据Box—BehnkenDesign（BBD）实验设计原理,采用3因素3水平的响应面法,以合成收率为响应值,分析各因素的显著性和交互作用。结果表明：最佳合成条件为反应时问10．38h,NaOH浓度1．14mol／L,Pd／C催化剂用量2．29g,此时NHDC的产率可达71．2％。     

Neohesperidin Dihydrochalcone Stability in Aqueous Buffer Solutions

The degradation of neohesperidin dihydrochalcone (NHDC) in solution was studied at different temperatures (30–60°C) and pH values (l–7). Pseudo-first order kinetics were observed across the temperature and pH range. Maximum stability was at pH 3–5. These data may be used to predict sweetener stability to typical conditions prevailing during manufacture and storage of beverages and to food processing at high temperatures. Results indicate NHDC would be stable throughout the normal shelf-life of soft drinks and would also withstand pasteurization and UHT processes.